Dear All,

I am currently working on a small academic project of Damage Detection of Bridge Structure using Vibration Frequency and Modes analysis and Finite Element method.

My questions are:

1) Is there any systematic approach to follow this problem?

2) How should I start making its mathematical model? I am considering a truss bridge. Is it appropriate to consider linear elastic deformation of simply supported beam at first point?

3) Is there any standard reference which can help me to construct its mathematical model?

Any help is appreciated. I am a very new learner for this type of problem. I do have some FEM background but having difficulty in constructing mathematical model. 

Thank you,

Bhavin 

The autovibrations of the bridge over Volga river in the city of Volgograd(Russia) were filmed (not by me) today on 05/21/2010. The amplitude reachedabout 1 m. The bridge opening was just six months ago...

Apparently, either the bridge frame drag was too high or torsional stiffness / damping too low.